Social inequalities in COVID-19 death by area-level income in 11.2 million people in Ontario, Canada: patterns over time and the mediating role of vaccination

Knowledge of patterns in COVID-19 deaths by area-level income over time and the mediating role of vaccination in inequality patterns remains limited. We used data from a population-based retrospective cohort of 11 248 572 adults in Ontario, Canada. Cause-specific hazard models were used examine the relationship between income (2016 Census at the dissemination area level) and COVID-19 deaths between March 1, 2020 and January 30, 2022, stratified by wave. We used regression-based causal mediation analyses to examine the mediating role of vaccination in the relationship between income and COVID-19 deaths during waves 4 and 5. After accounting for demographics, baseline health, and other social determinants of health, inequalities in COVID-19 deaths by income persisted over time (HR [95% CI] comparing lowest income vs highest income quintiles were 1.37 [0.98-1.92] for wave 1, 1.21 [0.99-1.48] for wave 2, 1.55 [1.22-1.96] for wave 3, and 1.57 [1.15-2.15] for waves 4 and 5). By the start of wave 4, 7 534 259 (67.7%) of those alive were vaccinated, with lower odds of vaccination in the lowest income vs highest income quintiles (0.71 [0.70-0.71]). This inequality in vaccination accounted for 56.9% [22.5%-91.3%] of inequalities in COVID-19 deaths between individuals in the lowest income vs highest income quintiles. Efforts are needed to address vaccination gaps and residual heightened risks associated with lower income to improve health equity in COVID-19 outcomes.

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Publication Details

Journal
American Journal of Epidemiology
Published
2025-03-04
DOI
https://doi.org/10.1093/aje/kwaf051
Citations
3
Primary Topic
COVID-19 epidemiological studies
Type
article
Field-Weighted Citation Impact
4.10
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article

Social inequalities in COVID-19 death by area-level income in 11.2 million people in Ontario, Canada: patterns over time and the mediating role of vaccination

Stefan Baral, Arjumand Siddiqi, Janet Smylie, Peter C. Austin et al.
3 citations
American Journal of Epidemiology
COVID-19 epidemiological studies
4.10
article

Social inequalities in COVID-19 death by area-level income in 11.2 million people in Ontario, Canada: patterns over time and the mediating role of vaccination

Stefan Baral, Arjumand Siddiqi, Janet Smylie, Peter C. Austin, Beate Sander, Andrew J. Calzavara, Korryn Bodner, Sarah Swayze, Linwei Wang, Sean P Harrigan, Hind Sbihi, Jeffrey C. Kwong, Sharmistha Mishra, Maria Koh
article en
3 citations

Abstract

Knowledge of patterns in COVID-19 deaths by area-level income over time and the mediating role of vaccination in inequality patterns remains limited. We used data from a population-based retrospective cohort of 11 248 572 adults in Ontario, Canada. Cause-specific hazard models were used examine the relationship between income (2016 Census at the dissemination area level) and COVID-19 deaths between March 1, 2020 and January 30, 2022, stratified by wave. We used regression-based causal mediation analyses to examine the mediating role of vaccination in the relationship between income and COVID-19 deaths during waves 4 and 5. After accounting for demographics, baseline health, and other social determinants of health, inequalities in COVID-19 deaths by income persisted over time (HR [95% CI] comparing lowest income vs highest income quintiles were 1.37 [0.98-1.92] for wave 1, 1.21 [0.99-1.48] for wave 2, 1.55 [1.22-1.96] for wave 3, and 1.57 [1.15-2.15] for waves 4 and 5). By the start of wave 4, 7 534 259 (67.7%) of those alive were vaccinated, with lower odds of vaccination in the lowest income vs highest income quintiles (0.71 [0.70-0.71]). This inequality in vaccination accounted for 56.9% [22.5%-91.3%] of inequalities in COVID-19 deaths between individuals in the lowest income vs highest income quintiles. Efforts are needed to address vaccination gaps and residual heightened risks associated with lower income to improve health equity in COVID-19 outcomes.

American Journal of EpidemiologyVol. 195(2)
University of North Carolina at Chapel Hill (US), St. Michael's Hospital (CA), Bloomberg (United States) (US), Sunnybrook Health Science Centre (CA), University Health Network (CA), Massachusetts Department of Public Health (US), 3M (United States) (US), Harvard University (US), University of British Columbia (CA), Johns Hopkins University (US), University of Toronto (CA), Li Ka Shing Foundation (CN), Hospital for Sick Children (CA), Health Sciences Centre (CA), BC Centre for Disease Control (CA), International Council for the Exploration of the Sea (DK), Health Solutions (Sweden) (SE), Public Health Ontario (CA), Institute of Population and Public Health (CA), St Michaels Hospital (GB), Unity Health Toronto, Institute of Medical Sciences (IN)
No poverty
Openalex Percentile: Top 7%
COVID-19 epidemiological studies
4.10
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